Mead Johnson Nutritionals has developed milk-based formulas in which part of the lipid has been replaced with sources of docosahexaenoic acid (DHA) and arachidonic acid (ARA). We hypothesize that the addition of these long chain polyunsaturated fatty acids (LC PUFA) will improve the growth and development of preterm infants. This study is a 2-phase, double-blind, randomized, controlled, parallel designed, prospective trial of infant formulas containing the LC PUFA DHA and ARA. The objectives of this study are to evaluate the safety and efficacy of feeding preterm infants formula supplemented with long chain polyunsaturated fatty acids (DHA and ARA) up to one year corrected age.